This invention relates to a process of converting a cellulose-containing biomass into a liquid useful as fuel or as a raw material for various chemical compounds.
Many studies have thus far been made on liquefaction of cellulose-containing biomass materials such as wood. For example, there is proposed a process in which a biomass is, after being dispersed in a recycled oil or after being hydrolyzed with an acid, heat-treated at a temperature of about 350.degree. C. and a pressure of a reducing gas (such as CO, H.sub.2 or a mixture thereof) of about 290 atm. The use of such a reducing gas is, however, disadvantageous from the standpoint of economy and safety. Further, the liquefied product obtained with such a conventional process contains a highly viscous solid mass, the removal of which from the product is quite difficult. Thus, the conventional process is not entirely satisfactory as an industrially applicable process.